This invention pertains to a mobile robotic platform operable in association with guide means mountable on a member for transporting an operative device relative to the member. More particularly, the mobile robotic platform has a travelling carriage which can mount any desired operative device, with examples of such devices being ultrasonic testing equipment, X-ray machines and welding equipment. Structure associated with the carriage and the guide means provides for accurately controlled travel of the carriage and with the control having a remote capability.